The power of teen (and tween) pop lit up Cynthia Woods Mitchell Pavilion at The Woodlands Sunday night – fueled by One Direction.

The perfectly coiffed quintet, assembled on the U.K. edition of “The X Factor,” is the latest in a never-ending cycle of boy bands designed to make girls sing along and swoon. There were also squeals, sighs and more than a few tears.

It was all earnest and squeaky-clean, save for a random blowup doll that was quickly, and angrily, swiped by security from a bouncing fan.

Girls showed up hours earlier, unaffected by the scorching heat, to buy merchandise, listen in on sound check and secure a good spot on the lawn. Within minutes of gates opening, not even a tiny patch of grass was visible. (Merchandise stands opened Saturday and early Sunday to meet demand.) They knew every lyric of every song.

The boys, playing before 20,000 people – their largest crowd so far – raced through high-energy, feel-good tunes, including “Na Na Na,” “Stand Up” and current single “One Thing.” To their credit, there were no flashy costumes or distracting sets. Pure energy often pushed things forward.

With just one album to pull from (released only a few months ago), they padded the set with covers, from the Black Eyed Peas and Kings of Leon to a sweet rendition of “Torn” from ’90s nymph Natalie Imbruglia There was also frequent chatter, shouts of “Howdy!” and Twitter questions from the crowd.

But it was when they launched into any number of soaring ballads – “I Wish,” “Moments,” “Gotta be You” – that the entire area seemed to lift off the ground. Cellphones lit up the lawn, and tears streamed down ruddy cheeks.

Ollie Murs, also a past contestant on “The X Factor” U.K., opened the show with a snappy set that combined Bruno Mars swagger and Robbie Williams cheekiness.

He was often winded between songs, likely due to the heat. Welcome to Texas.

In case one show wasn’t enough, One Direction will be headed back this way in July 2013. Tickets are already on sale.